Recently, as electronic equipment has been reduced in size, small-sized high-frequency capacitors having large capacitance have been demanded. As such capacitors, a solid electrolytic capacitor using a solid electrolyte layer made of a conductive polymer has been proposed, which comprises a positive electrode, a dielectric layer, and the solid electrolyte layer that is formed on the dielectric layer. In the solid electrolytic capacitor, the positive electrode is composed of a sintered body of valve metal such as tantalum, niobium, titanium, and aluminum, and then the dielectric layer is formed by anodizing a surface of the positive electrode.
A positive electrode lead connecting to the positive electrode terminal is disposed in the positive electrode. In Unexamined Japanese Patent Publication No. 4-42520, a technology which uses a positive electrode lead made of niobium and the like, which is a valve metal different from tantalum, applying for a positive electrode made of tantalum is proposed in order to enhance adhesion between the positive electrode and the positive electrode lead.